Control circuit for step-by-step switches



Feb. 20, 1951 H. B; BROWN 2,542,794

CONTROL CIRCUIT FOR STEP-BY-STEP SWITCHES Filed NOV. 18, 1944 /A/l/ENTOR y H 5. BROWN Patented Feb. 20, 1951 CONTROL CIRCUIT FOR STEP-BY-STEP SWITCHES Henry B. Brown, Madison, N. J., assigner to Bell Telephone Laboratories,

Incorporated, New

York,n N. Y., a corporation of New York Application November 18, 1944, Serial No. 564,139

4 Claims. l This invention relatesl to firing control mechanisms and particularly to mechanisms for rins fuses employed in igniting explosive charges.

An object is to simplify the construction and operation of ring mechanisms and to improve of the fuses in any one of said series for each hand operation of said mechanism.

The applicants invention has been illustrated in the accompanying drawings in which Fig. 1 shows a typical arrangement for firing various groups of fuses and Figs. 2, 3- and 4 show various positions of a hand-operatedswitch employed in this system for selecting groups of fuses to be fired. l

Referring now to the drawings, Fig. 1 shows four different groups of fuses, groups l, 2 and 3, consisting of four fuses each and group 4, consisting of eight fuses, a mechanism for ring any selected group or groups. This mechanism consists generally of a gro-up of operatir keys l2, a. step-by-step switch I3, a hand-operated switch |4 and circuits, control lamps and relays for eecting'the various. operations.

This mechanism operates as follows: f itis desired for example to start firing the rst group I, and either stop after this group is nred or continue to fire the succeeding groups ,2,` 3 and or any number of these groups, the so-called group hand-operated switch I4 is set as shown in Fig. l. A connection is thereafter established between contacts l5 which contacts maybe closed by any suitable arrangement such as for example a door or doors (not shown) which may normally cover the ruses and the associated rockets if the fuses are used for this purposeand which may be opened when the ring begins. This arrangement of doors may be provided so that any acci-Y dental operation of the key mechanismV will not set oli the fuses until the mechanism'is actuallyr in readiness for functioning. Then the start key itV is operated. This causes the establishing of a circuit for the lighting of lamp 1", from. battery, contacts I5, key I6, lamp ll, key (6to (Cl. F-375) ground. Relay 20 is also operated over a circuit from battery, contacts |5, key I6, the firing plunger key 2|, winding of relay 20, resistance 22, key I6 to ground. If the second makeready key 23 is operated the lamps 24 and 25 are lighted over a circuit from battery, contacts l5, key I6, lamps 24 and 25, keys 23 and I6 to ground. The key 2S is then operated and the circuits are now ready for the firing of the rlrst group by the operation of ring key 2|. The operation of key 2| releases relay 20 and causes the operation of select magnet 30 for the stepping of the switch i3, and the ring of the fuses. The circuit for stepping magnet 30 extends from battery, contacts |5, key I6, ring key 2|, contacts of relays 20 and 3|, key 23, winding of magnet 30, resistance 22, key I6 to ground. Relay 32 is then operated over a circuit from battery, contacts I5, key I 6, contacts of magnet 30, winding of relay 32, contacts of key 23, resistance 22, key I6 to ground. Relay 32 in operating closes a circuit for the operation of relay 3| from bat` tery, contacts l5, keys I6 and 2|, contacts of relays 20 and 32, winding of relay 3|, resistance 22, key I6 to gro-und. Relay 3| closes a, circuit for the operation of relay 33 from battery, contacts I5, keys |6 and 2|, contacts of relays 20 and 3|, winding of relay 33, resistance 22, key l5 to ground. As relay 3| operates the circuit of stepping magnet 30 is opened and this steppingr magnet releases causing the brushes of switch |3 to'take one step to advance them to the rst position. At this time, that 'is as soon as relay 33 operates, a, first fuse 34 in group is fired over a circuit from battery, contacts l5, key I6, key 2|, contacts of relay 20, key 23, contacts of relay 33, resistance 35, brush 36, first terminal of theV associated bank, fuse 34, key I6 to ground. Then after an interval relay 32 releases due to the release of stepping magnet 30 and this relay in releasing releases after an interval relay 3|. Both these relays 3| and 32 are slow in releasing. On the release of relay 3|, relay 33 is released. On the release of relay 3|, the stepping magnet 30 is again operated and this cycle of operations of the relays 3| 32, 33 and stepping magnet 33 are repeated to step the brushes of the switch I3 to succeeding terminals to lire the succeeding fuses.

If now after firing of the fourth and last fuse in. group I, which is fuse 38, it is desired not to fire any more fuses, key 2| may be released. Should the operator, however, desire to re one or more of the succeeding groups of fuses, he will maintain the firing key 2| operated for this purpose and the switch i3 will be stepped, by the operation and release of the above-mentioned relays and the stepping magnet 3|), to continue the firing until key 2| is released. In any case as soon as firing key 2| is released, the stepping mechanism may be returned to normal without firing any of a the remaining fuses by the release of keys 26 and 23. OnI the release of key 2| the circuit for the operation of relay is reestablished and the stepping magnet is'operated on the re- K leased key 23 from battery, contacts I5, key I6, f 10 self-interrupting contacts of stepping magnet 30, the twentieth terminal 4I of the bank associated with brush 40 and this brush if all the fuses have been fired, contacts of key 23winding of stepping magnet 3|), resistance 22, key I6 to ground.v If, l5 however, only thelrst group of fuses have beenn fired, the switch would naturally have its brush 42 on terminals 43 as it would have taken only four steps. In this case the connection from the self-interrupting contacts of the stepping magnet 20 30 for the operation of this magnet will extend to the fourth terminal 43 to brush 42, key 23, and through the select magnet, resistance 22, key

-I6 to ground. This would cause the switch to take one step and when the brush 42 lands on 25 terminals 44, a connection is established over this terminal for the self-interrupting contacts through brush 42 contact 45 and brush of switch VI4 over the same circuit to step the switch another step. 'After this the circuit will be estab- 30 `lished over the succeeding four terminals of the K bank associated with brush 42 and as it advanced to terminal 46, the circuit is extended through switch I4 over terminal 4l then four more steps are taken over the next four terminals of the bank associated with brush 42 and when the brush lands on terminals 48 another connection is established through switch I4 o ver terminal 49 and then the succeeding eight steps are taken by the connections through the remaining eight 44|' terminals and brush 42 until the switches have taken half a turn and then the connections are established through brush and associated bank terminals until the switches return to normal.

If it is now assumed that the operator does not want to re the four rst fuses in the first group I, but desires to fire the four fuses of the succeeding group 2 he will set the switch I4 to the position shown in Fig; 2 of, the drawing and 50 only operate key VI 6. As soon as key I6 is operated the lamp I'I lights as before and stepping'magnet 3G will now operate over a circuit from battery, contacts I5, key I6, self-interrupting contacts of the stepping magnets of the stepping magnets 55 30, the brush and first terminal 50 of switch I4, the first terminal 5| and brush 4I) of the stepby-step switch I3, contacts of key 23, winding of stepping magnet 30, resistance 22, key I6 to ground. This caused the switch I3 to take one ou step, disconnecting the brush 40 from terminal 5I and as brush 42 lands on the rst terminal 52, another circuit is closed through the selfinterrupting contacts of stepping magnet 30 independent of switch I4 to cause the stepping 65 magnet to take another step. The stepping of switch I3 is continued for another four steps past the terminal 43 and when the brush 42 lands on the terminal 44 as there is no connection for this terminal through switch I4 at this time the step- 70 ping will be discontinued and the switch stopped. As soon as the switch stopped the operator will operate the keys 23 and 26 to prepare the circuit for the ring of the succeeding groups of fuses, that is, group 2, and as soon as the iiring key 2| 4'5 is operated in the same manner as the fuses in group were iired. The firing of the succeeding groups will be continued if the operator so desires, but he may stop the ring at any point by releasing the ring key 2| and then the switch is returned to normal on the release of key 23 in the manner as hereinbefore described.

If it is` desired to omit the firing of the fuses in groups I and 2 and instead lire the fuses in group 3, the switch I4 may be set to the position shown inv Fig. 3.' In this case the switch I3 will take the rst ve steps as before and when the brush 42 lands on terminal 44, a connection will be establishedv through switch I4 over the terminal 45 and thus the switch will take anotherV step and continue another ve steps until brush 42 lands on terminal 46 which has no connection through switch I4 and thus stops at this point for the ring of the remaining groups by Vthe operation of keys 23, 26 and 2| as described. On the other hand if the last eight fuses in group 4 only are to be red switch I4 is set as shown in Fig. 4 the switch I3 will therefore step untilthe brush lands on terminal 48 where there is no connection for the stepping magnet 33 which will then stop and the ring of this last group may then be started by the operation of keys 23, 26 and 2| as usual.

If it is desired to fire only one fuse for each operation of the ring key 2|, the procedure would be, for example, if the first fuse in group is to be red, instead of operating key 26 with the other keys and then operating the firing key 2|, this key 26 would be retained in normal position. Therefore, after the release of relay 32 when the stepping switch has taken one step, relays 3| and 33 will not release as a holding circuit will be established for these two relays in parallel from battery, contacts I5, key I6, key 2|, contacts of relay 20, contacts of the operated relay 3| through the winding of relay 33, resistance 22, key I6 to ground for `holdingrelay 33 and through contacts of relay 3|, key 26, contacts of released relay 32, winding of relay 3|, resistance 22 key I6 to ground. These relays will be maintained operated as long as the ring key 2| is maintained operated. When the key 2| is then released, relay 20 reoperates and relays 3| and 33 are released. If itisthen'desired to re additional fuses key 2| is again operated, the switch will then take another step by the operation of the stepping magnet and relays 32, 3| and 33 as usually and relays 3| and 33 will lock up until the key 2| is again released. Thus succeeding fuses may be fired for each operation of the firing key 2|. If it is decided that only one fuse is to be red or that the firing of fuses is to be stopped after any desired number of fuses have been lired by corresponding succeeding operations of key 2|, lthe. switch I3 may be returned to normal as hereinbefore described.

What is claimed is: n'

1. A control mechanism for controlling electrical circuits comprising a step-by-step switch having contacts at step positions thereoL'electric means for stepping said switch, relay means and a key mechanism in circuit with and operable for controlling said stepping means to step said switch normally continuously and automatically` into successive engagement with each contact thereon, some contacts on said switch adapted to have circuits connected thereto to be controlled by said switch, and a settable selector, a plurality of special contacts on said switch, ea'ch special contact disposed between consecutive groups of said some contacts, said selector arranged to interconnect some of said special contacts with the circuit of said stepping means and arranged thereby to stop the stepping of said switch when said switch engages the iirst of said speciai contacts not interconnected by said selector with the circuit of said stepping means.

2. A control mechanism for controlling electrical circuits comprising a step-by-step switch having contacts at step positions thereof, electric means for stepping said switch, relay means and a key mechanism in circuit with and operable for controlling said stepping means to step said switch normally continuously and automatically into successive engagement with each contact thereon, some contacts on said switch adapted to have circuits connected thereto to be controlled by said switch, and a settable selector, at least two special contacts on said switch, said special contacts disposed between consecutive groups of said some contacts, said selector arranged to interconnect one of said special contacts with the circuit of said stepping means and arranged thereby to stop the stepping of said switch when said switch engages the other of said special contacts.

3. A control mechanism for controlling electrical circuits comprising a step-by-step switch having contacts at step positions thereof, electric means for stepping said switch, relay means and a key mechanism in circuit with and operable for controlling said stepping means to step said switch normally continuously and automatically into successive engagement with each contact thereon, contacts on said switch adapted to have circuits connected thereto to be controlled by said switch, and a settable selector interconnected with said switch and with the circuit of said stepping means and arranged to stop the stepping of said switch after a number of steps thereby predetermined by a setting of said selector, said key mechanism reoperable for controlling said stepping means to further step said switch under similar control of the same setting of said selector.

4. A control mechanism for controlling electrical circuits comprising a step-by-step switch lli having contacts at step positions thereof, electric means for stepping said switch, relay means and a key mechanism in circuit with and operable for controlling said stepping means to step said switch normally continuously and automatically into successive engagement with each contact thereon, some contacts on said switch adapted to have circuits connected thereto to be controlled by said switch, and a settable selector, a plurality of special contacts on said switch, each special contact disposed between consecutive groups of said some contacts, said selector arranged to interconnect some of said special contacts with the circuit of said stepping means and arranged thereby to stop the stepping of said switch when said switch engages the first of said special contacts not interconnected by said selector with the circuit of said stepping means, said key mechanism reoperable for controlling said stepping, means to further step said switch under similar control of the same setting of said selector.

HENRY B. BROWN.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 257,695 Haight May 9, 1882 513,294 Bertolini Jan. 23, 1894 808,275 Dodson Dec. 26, 1905 1,078,463 Rawson Nov, 11, 1913 1,369,658 Hoar Feb. 22, 1921 1,438,833 Kaminski Dec. 12, 1922 1,581,421 Snyder et al. Apr. 20, 1926 1,901,185 Nelson Mar. 14, 1933 2,085,442 Newell June 29, 1937 2,318,541 Tewkesbury May 4, 1943 2,362,690 Fichter Nov. 14, 1944 2,433,805 Woli Dec. 30, 1947 FOREIGN PATENTS Number Country Date 1,713 Great Britain 1888 422,392 Germany Dec. 1, 1925 567,251 Germany Dec. 30, 1932 

